In general, you take relief for one rule at a time. If taking relief from one condition puts you into a position where you are entitled to relief under another rule, you then follow the procedure for that rule. See decision below.
In the case described one would:
A) Find the nearest point of relief for the ball on the cart path and drop according the procedure.
B) Determine if the fence interfered with the stance, swing or lie from the new ball position. If yes, find the nearest point of relief from the fence and drop according to the procedure.
Note that B assumes the fence is not a boundary fence and has not been designated as an integral part of the course (unlikely with a fence, but can happen with things like stone walls).
Nearest Point of Relief from Cart Path Is in Casual Water; Nearest Point of Relief from Casual Water Is Back on Cart Path
Q.A player's ball lies on a paved cart path from which he wishes to take relief under Rule 24-2b(i). It appears that the nearest point of relief will be in a large area of casual water which adjoins the cart path and the nearest point of relief from the casual water under Rule 25-1b(i) would be back on the cart path. What are the player's options?
A.The player may proceed in accordance with Rule 24-2 and then, if applicable, Rule 25-1. He is not entitled to take relief from both the immovable obstruction and the casual water in a single procedure, unless after proceeding under these Rules, the player is essentially back where he started and it is evident that such a procedure is necessary to obtain relief from both conditions.
Therefore, the player should proceed as follows:
1. He may lift and drop the ball in accordance with Rule 24-2b(i) in the casual water.
2. He may play the ball as it lies or take relief from the casual water, in which case he would lift and drop the ball in accordance with Rule 25-1b(i).
3. If the ball when dropped comes to rest in such a position that there is interference by the cart path, he may play the ball as it lies or proceed in accordance with Rule 24-2b(i). If the nearest point of relief is in the casual water, as an additional option, the player may, in equity (Rule 1-4) obtain relief without penalty as follows: Using the new position of the ball on the cart path, the nearest point of relief from both the cart path and the casual water shall be determined which is not in a hazard or on a putting green. The player shall lift the ball and drop it within one club-length of and not nearer the hole than the nearest point of relief, on a part of the course which avoids interference by the cart path and the casual water and is not in a hazard or on a putting green.
If the dropped ball rolls into a position where there is interference by either the cart path or the casual water, Rule 20-2c applies.
The same principle would apply if there was interference from any two conditions, i.e., casual water, a hole made by a burrowing animal, an immovable obstruction, from which relief without penalty was available and in taking relief from one condition it resulted in interference from the second condition.